Electrical apparatus



April 13, 1954 R. M. PURDY ELECTRICAL APPARATUS Filed April '7, 1951 Oda @6m ATTORNEY.

Patented' Apr. 13, 1954 UNITEDv STAT-ES PATENT OFFICE ELECTRICAL APPARATUS Rolland: rurd'y, 'B:nnbrnllgal N. Y.; assigner to Bendix AviatonfCorporation; New-York,` N; Y;, a coi-'poration of `Delaware Application Aprila, 1951, serial No. 219,883

This invention relates to electrical apparatus and more particularly to meansin an ignition distributor for internal combustion engines for transmitting electrical current between stationary parts through rotating or movable parts for the purpose of effecting and controlling the distribution of electrical current impulses to a plurality of circuits in sequence.

One of the objects of thepresent invention is to provide in an ignition distributor unit or the like novel means for mounting spring pressed current-carrying brushes of carbon or like material in a movable part, such as a rotor, whereby said brushes will not become disassociated from said part during assemblyrfand disassembly of the unit. I n

Another object of the invention is to provide in an ignition distributor unit a -novell rotor which is of simple construction, in-zxperisive t0 manufacture, composed l Yof a relatively small number of parts, and reliable in operation, l

Another object'is toV provide a novelly constructed ignition distributor rotor which maybe made for the most part of metal andwherein a pair of spring pressed brushes maybe mounted for sliding movement and electrically connected together to transmit electrical energy from one stationary conductor to another. t v

A further object is tofprovide in an ignition distributor unit or the like for a multiecylinder internal combustion engine novel means for mounting current-carrying brushes'of carbon or like material inthe rotor of said unit, said means including springs for applying yieldable pressure to said brushes and serving alsov as conductors to electrically connect said brushes, thereby sim-V plifying the construction of therot'or'and rendering the latter less expensive to manufacture.

A still further object is to provide apparatus of the above character embodying novelly constructed and novellyvfunctioning spring means for controlling the sliding action of a carbon brush or the like to insure against tiltingof ythe brush and consequent bindingr thereof inits guide. t v

The above and further objects and novel features of the invention will `more fully. appear from the following detaileddescription when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition ofthe limits of the invention.

In' the drawings, wherein like reference characters refer to like 'parts throughout -the several v1ews,

Fig. 1 is a front elevation view of one form of distributor rotor constructed in accordance with the present invention;

Fig's'l 2'a'nd 3 are detail sectional views of portions ofthe' rotor of Fig. 1, the sections'being takenv substantially' on lines 2`2 and 3 3, respectively, of Fig. 1;

Fig'.'4 is a front elevation view of another form of distributor rotor constructed in accordance vwithv the invention; and y Figs. 5 and 6are detail rsectional views of the embodiment'of Fig. 4, the sections being taken substantiallyon lines 54-5 and 6 6, respectively, of Fis". 4. t

Thepre'sntinvention is illustrated in the accompanying drawings, by way of example, in the formof a distributor rotor of the type employed inv connection with an electrical current distributing unit which is adapted for use in the ignition system of a multifcylinder internal combustion engine, and particularly the `type wherein relatively low tension current is distributed from a common source to a plurality'of spark plug circuits in sequence. In the form shown in Figs. 1 to f3, the novel distributor rotor indicated `generallyat 9 `consists primarily of an elongated block I0 which may be of metal to provide strength accompanied by smallness to conserve space. Block I0 carries two identical pairs of carbon or like electrically conductive brushes I I, I2 and I4, I5 adjacent opposite ends thereof for pickingv up electrical current from a suitable source of electrical energy and conducting the same to the spark plugs in the engine cylinders in a-manner well understood in the art. In the illustrated embodiment, brushes II and I4 may function as the input or pick-up brushes for receiving electricalenergy from concentric conductive rings (not shown) connected to the same or different sources of electrical energy, and the brushes I2 and I5 may act as the output brushes which engage circumferentially spaced segments of the distributor for directing current to a plurality of spark plugs in sequence.

Rotor block I0 isprovided with a central openingfiIS for receiving the driven rotor shaft of a distributor unit (not shown) and with a keyway II whereby the rotor 9 may be removably mounted on the shaft for rotation therewith. Each of the brushes II, I2, I4 and I5 is mounted in rotor block- I0 in like manner, and brush II will be taken as illustrative forA detail description. rlhe brush is preferably cylindrical and slidably pro jects into and from an insert I 8 of insulating material-l The reducedcylindrical end I9 of said insert has a cylindrical bore and projects beyond one face of block I0. 'I'he other and larger end of insert I8 is ilush with the other face of block I and has tapered or cone-like bore 20. A cone-shaped coil spring 2| rests against the tapering walls of conical recess or bore when the spring is extended and the small or innermost coil or turn thereof closely surrounds and is preferably soldered or otherwise suitably secured to the reduced inner end of brush |I, as best seen in Fig. 2. Spring 2| thus supports brush and holds it against outward movement beyond the illustrated position .while yieldably resisting the inward movement of the brush. The construction ofth'efspring' ispreferably but not necessarily v'suchthat each coil or "1 turn thereof will t within the next larger turn or coil so that a comparatively-:flat and `strong spring can be designed to occupy are1atively narrow space in the direction of the axis of rotation of the lrotor rwhile permitting ample axial movement oftliebruh. jj 'p At least 'apart ofv the outer' and largest coil or turn of springmZI rmay engage'theend surface of'v insert `I8 within an opening in an insulating plate 22. said opening .beir 1g of slightly 4greater diameter than the outer end ofbore or'recess 2|) and of lesser diameter than the outside diameter offthe same, end 'of'- insert t8. A ymetallic `cover plate 23 engages the other `surface of plate 22 and serves to hold spring 2| in place.'` Cover 23 may havegan opening 24 therein, if desired, At the other facefof thei'rotor an insulating plate 22a and a metalliccover or retaining plate 23a, identical with plates, 2] and23 respectively, but turned .end fo! end' .rell'fiv therein. have Openings which receive the projecting end I9 of insert I8. The other end of plates Maand 23a cooperate with the brus'hf-I2 and its` spring 2Ia in the same manner that plates 22 and 23 cooperate with brush anditsspring, 2|. y The above described parts are secured together by a pair of rivets 26, 26 or other equivalent means. The Shanks of th'rivet's between plates 22 -and 22a are preferably surrounded by insulating bushings 21 .to insulate the-same frommetallic rotor body |||4-. It 4will-thusA be seen that electrical current picked upY by brush I for example, willlbe `conducted through spring 2 I cover plate 23, rivets 26, 26, cover plate 23a and spring 2|a to brush l2. Hence, current may be conducted from a stationary ring engaged by brush I I at one side of the rotor to circularly arranged arcuate segments engageable by brush I2 at the other side of the rotor.

In the embodiment of Figs. 4 to 6, the rotor 29 comprises a body 30 of insulating material, such as hard rubber, bakelite or the like. A bushing 36 having a keyway 31 is provided in rotor 29, 30 for drivably mounting the same on the distributor or other shaft. The current conducting brushes 3|, 32, 34 and'35 which correspond with brushes II. I2, I3 and I5 of Fig. 1 are mounted for sliding movement in cylindrical portions of openings 38, 38 in body`30. Opposite ends of passages 38 are cone-shaped, as atv 40, and have internal shoulders 39 near the enlarged ends thereof. A conical coil spring 4| like spring 2| is seated in the cone-shapedrportion of each bo-re 38 with the smallest or 4innermost coil thereof secured to the inner end of a brush, such as brush 34. The largest or outer coil of each spring 4| engages a shoulder 39 and is held in place by a metallic cover plate 43 or 43a, which plates are electrically connected and secured to opposite faces of body 30 by a pair of rivets 46. 46. If desired bosses 41, 41a may be provided on body 30 to project into openings in cover or spring retaining plates 43, 43a, respectively.

It will thus be seen that electrical current supplied to brush 34, for example, at one side of rotor 29 will be conducted by spring 4|, retaining plate 43, rivets 46, retainer plate 42a and a second spring 4| to brush 35 at the other side of the rotor. Thus, brushes 3| and 34 maypick up energy from concentric rings at one side of the rotor for conduction to concentric rings of spaced arcuate segments, for example, engaged by brushes 32 and 35 at the other side of the rotor during krotationof the latter.

There isi thus provided an ignition distributor rotor or the like wherein current carrying brushes of carbon or other conductive material are novelly mounted for conducting electrical current between stationary elements at opposite sides of the rotor. Additionally, each brush is associated with spring means novelly mounted in the rotor and connected withthe brush to insure proper operation of thelatter during long periods of use.` The-novel' mounting of the springs and brushes 4is such that sticking or binding of the brushes in their guides is substantially eliminated and such vvthat the Vbrushes are-suitably maintained within therotor when the latter is disassembled from the distributor-or other unit. Other features are the light weight of the construction and the small space required "there,- for. The simplicityothe novel construction hereby provided facilitates and speeds up assembly Vof the'rotor and-red1ices-4 the costover 4cornparable prior devicesi'for the samefuses;

Although only, a limited number 'of embodiments of theV invention*r are illustrated in the accompanying drawings and described in `the foregoing specification, it iswto be expresslyunderstood that the invention is not limited to these embodimentsvo'r-"totlie specic use thereof in connection with an ignition distributor unit for internal combustion engines. For example, the reciprocable brushes may, if desired, 'have flats or other means onthesides thereof cooperating with similar flats crlmeans on the inserts I8 or rotor body 30 forpreventing any turning of the brushes about their own axes. Various other changes, particularly in the design and arrangement of the parts illustrated, may be made without departing from theispirit and scopeof the invention as will now be apparent to those skilled in the art. For a definition of the limits of the invention, reference is had primarily to the appended claims.

What is claimed is:

l. In a device ofthe class described, an. electrically conductive brush. an insulating` block having an opening therethrough, an end portion of said opening being shaped to slidably receive an end portion of said brush, the other end portion of said opening being cone-like with the walls thereof diverging toward the face of the block, a. cone-like coil spring in said cone-like portion of said opening and having turns thereof seated on the walls of said opening when the spring is extended, the smallest turn of said spring being secured to said brush. and means at the enlarged end of said opening for securing said spring in the opening.V

2. In a device of the class described, a block comprising insulating material having a funnelshaped opening therethrough, an electrically conductive brush slidably mounted in the reduced portion of said opening and projecting therefrom, a cone-like coil spring in the erilarged portion of said opening normally under compression and having turns thereof seated on the cone-like wall of said enlarged portion of the opening when the spring is extended, the smallest turn of said spring being secured to said brush, and means at the enlarged end of said opening for securing said spring in the opening.

3. In a device o the class described, an insulating block having an opening therethrough, said opening having an annular internal tapered shoulder, an electrically conductive brush slidably mounted in said opening and projecting from one end thereof, a cone-like coil spring with successive turns adapted to simultaneously engage said tapered shoulder when the spring is extended, the smallest turn of said spring being secured to the end of said brush in the opening, and means for anchoring the largest turn of said spring, whereby movemf. nt of said brush into said block is yieldably resisted by said spring and movement of the brush out of said block is limited by the engagement of the spring with said tapered shoulder.

4. A device as defined in claim 3 wherein each turn of said spring will t within the next larger turn thereof when the spring is compressed upon movement of the brush into the block.

5. A device as defined in claim 3 wherein said anchoring means comprises a plate secured to the block, at least a portion of said largest turn of the spring being interposed between said block and plate.

6. In a device of the class described, a block comprising insulating material with spaced openings having parallel axes in said material, each of said openings having an annular internal tapered shoulder, said shoulders facing in opposite directions, an electrically conductive brush slidably extending into the reduced portion of each of said openings, one of said brushes projecting from said block in one direction and the other brush projecting therefrom in the other direction, a cone-like coil spring seated on each said shoulder and secured at its small end to one of said brushes, and means for anchoring the large ends of said springs in said openings, said anchoring means including an electrically conductive plate on each face of said block in electrical contact with a said spring and electrically conductive means connecting said plates and securing the same to said block, whereby said brushes are electrically connected through said springs.

7. A device as defined in claim 6 wherein said block comprises a metallic body and said insulating material is in the form of tubular inserts in said body.

8. A device as defined in claim 7 comprising means for insulating said plates and connecting means therefor from said metallic body.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,073,678 Harvey Sept. 23, 1913 1,928,678 Sjolander Oct. 3, 1933 2,549,871 White Apr. 24, 1951 FOREIGN PATENTS Number Country Date 250,665 Great Britain Apr. 15, 1926 

